I'm really convinced that I'm being toyed with by a community software

[Lilly]

@sadie

nesting more than 2 levels of categories

@Heliosurge

There is a command line to allow nesting subcategories beyond just 1 level.

I think you mean this?

@JammyDodger

cd /var/discourse/

./launcher enter app

rails c

SiteSetting.max_category_nesting = 3